1. Field of the Invention
The present invention relates to a magnetic recording and reproducing device and, more particularly, to a compact device for recording and reproducing signals using a tape cassette in which the recording and reproducing heads are inserted into the tape cassette.
2. Description of the Background
Heretofore, efforts have been made to reduce the size of magnetic recording and reproducing devices, particularly video tape recorders (VTRs), for better portability. To obtain such a reduction in size, it has been customary to reduce the size of the deck mechanism that includes the tape transport system.
Various approaches have been followed in attempting to reduce the size of the deck mechanism and such prior attempts include a reduction in the size of the tape cassettes being used, a reduction in the diameter of the rotary head drum, and a more effective utilization of the dead space present in existing tape cassettes.
The proposal to reduce the size of the tape cassettes requires an adapter or a mechanism for moving the reel supports to cause the distance therebetween to match the smaller, different cassette size, so that compatibility between different cassette sizes is ensured.
According to the attempt to utilize the dead space in existing tape cassettes, a rotary head drum and a tape loading mechanism are partially inserted into the dead space in a tape cassette that has been loaded in the magnetic recording and reproducing device.
The use of tape cassettes of reduced size results in a complex operating procedure and a complex operating mechanism, because an adapter must be used or a reel support moving mechanism must incorporated.
The effort to reduce the diameter of the rotary head drum is subject to design limitations, because when a standard-size tape cassette is used there is a certain limitation imposed on the transport of the tape by the diameter of the rotary head drum around which the tape is wound.
The utilization of the dead space in existing tape cassettes to receive a portion of the rotary head drum and tape loading mechanism is an effective way to reduce the size of the deck mechanism, however, the extent to which the rotary head drum and the tape loading mechanism can be inserted into a tape cassette is limited by the dead space available. In addition, in such proposed mechanisms, the tape cassette is loaded onto one chassis, and the rotary head drum and the tape loading mechanism are supported on another chassis, the two chassis being movable with respect to each other. These two chassis have respective mating surfaces that bear the chassis, but the mating surfaces require overlapping portions that result in a device of greater than desired width.
More specifically, if the overlapping portions of the mating surfaces are too small then when the chassis are moved relative to each other, the chassis would tend to swing and become unstable and would not move back smoothly, thus preventing the rotary head drum and the tape loading mechanism from being reliably inserted into the tape cassette. In view of this drawback, the overlapping portions of the mating surfaces of the chassis have to be relatively large and, hence, the surface areas of the chassis must also be large. Increasing the surface areas of the chassis, however, results in an increase in the size of other components, presenting an obstacle to the efforts to reduce the size of the magnetic recording and reproducing device.
Furthermore, a conventional VTR tape cassette is loaded in the unit while the lid is held in the raised position against the resiliency of the lid closing spring, and the tape is withdrawn from the opening of the tape cassette, or recording and reproducing heads are inserted into the opening of the tape cassette, so that signals can be recorded on or reproduced from the tape. During the time the tape is being withdrawn from the cassette housing or the recording and reproducing heads are being inserted in the cassette housing, the tape cassette has to be held in a stable manner in the loaded position. Because the tape cassette is required to be retained in position under retentive forces strong enough to overcome the moment resulting from the resiliency of the lid-closing spring, the cassette loading unit needs a retentive biasing means for guiding the tape cassette into the loaded position and retaining the tape cassette reliably in the loaded position. As a consequence, the deck mechanism which constitutes the cassette loading unit is complex in structure and large in size.